29 June 2018. A new experiment with Atlantic silversides (Menidia menidia) starts and as usual, it’s an all hand on deck operation. This time, we have Chris Tsang shadowing all of us and Emma professionally explaining the process.
Have a look for yourself!
14 June 2018. Members of the Baumann and Mason lab went on a trip to Mumford Cove, today, and Chris Tsang went along with his GoPro. Thanks to Charlie, the skipper, the ride was smooth and a pleasure, a swapping our pH, Temperature, oxygen, and salinity sensor was successfully swapped with a new one recording for the next weeks in 30 minute intervals. Wes Hoffman from the Mason lab, collected zooplankton with a Bongo-net. Sydney Stark, our NSF-REU student this summer, came along just for the fun.
See the fun for yourself!
The 282 fish are now split in a DNA sample for extraction and a body sample for further trait measurements.
On 18 May 2018, the Baumann lab teemed with activity. Maria Akopyan from Cornell University was busy phenotyping juvenile silversides for our Menidia Gene project. Mia and Mackenzie were busy working up field samples of silversides. And Hannes prepared adult silverside samples for later analyses.
Starvation rates in larval and juvenile Atlantic silversides (Menidia menidia) are unaffected by high CO2 conditions.
Marine Biology 165:75-83
26 March 2018. Today we got our first glimpse of an incredible new way of imaging the inner calcified structures of a fish body, particularly the ear bones (otoliths), of which every teleost fish has six, three on each side inside the skull. Otoliths are long known to fish ecologists for their properties to record and store information about a fish’s age, growth and habitat. With an adult Atlantic silverside, Hannes visited John Shepherd, facilities scientist and member of the Goldhamer lab at UConn, Storrs (Biology Physics Building), who showed us the use of a new, state-of-the-art micro CT-scanner (IVIS). Turns out, the system effortlessly imaged all six otoliths inside of the fish’s head. Later in the year, we will use the technique to image silversides reared at contrasting CO2 conditions to see whether they differ in their otolith size, volume, and structure. Thank you, John, for this truly inspiring demonstration!
This research feature makes the case for multistressor research to a broad general audience and introduces our NSF project and its participants. Download the feature by clicking on the pictures or the link below.
On this dimly lit November afternoon, rain mercilessly drenched scientists and crew on board the R/V Auk as it slowly navigated the waters of Stellwagen Bank. A world like a wet sponge. Sky and ocean, indistinguishable.
Thanksgiving, the next day.
Despite the circumstances, the team’s mood was nothing short of elated. Our small beam trawl had just spilled hundreds of silvery fish on deck, wriggling like eels. They were Northern sand lance (Ammodytes dubius).
Running ripe adults.
Spawning.
Apparently, they like Thanksgiving, too.
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As the ship docked back in the Scituate, Mass., harbor that day, the rain thinned to hazy darkness.
“Let’s get a coffee and then on the road,” mumbled Chris, who led the team, “the real work of the experiments has just begun.”
Sand lance have a few interesting and rare characteristics. They alternate between schooling and foraging in the upper water column and extended periods of being almost completely buried in sand. For that, they rely on sand of a particular grain size and with very little organic content. It’s the kind of sand that defines large areas of the Stellwagen Bank.
Surprisingly little is known about the ecology and ecosystem importance of this sand lance species, although research on its European relatives (A. tobianus, A. marinus) is more advanced. In particular, experiments on early life stages of Northern sand lance have been lacking, save for some pioneering work on rearing methods of the related A. americanus (Smigielski et al. 1984). One question that was of particular interest to our lab involved the potential sensitivity of this fish species to carbon dioxide (CO2). That’s due to two other interesting and rare characteristics of sand lance. They spawn in late fall and winter in cold (and still cooling) waters, which is why their eggs and larvae develop extremely slow compared to other, more typical spring and summer spawning species. In addition, the species is found not in nearshore, but offshore coastal waters, where smaller seasonal and daily CO2 fluctuations more closely resemble oceanic conditions. Could sand lance offspring be particularly sensitive to higher levels of oceanic carbon dioxide predicted during the next 100 to 300 years as climate change effects intensify?
Our experiments are still ongoing, and rearing protocols are being improved.
The preliminary findings, however, are stunning. Survival to hatch was dramatically reduced under elevated and high compared to baseline CO2 conditions. It was severely lowered at higher (10°C or 50°F) compared to lower temperatures (5°C or 41°F). Our second experiment this year appears to repeat this pattern. If these results continue, that would mean sand lance is one of the most CO2-sensitive species studied to date.
General interest in sand lance goes beyond its sensitivity to carbon dioxide. Given the species importance for the ecosystem and coastal economy, there are now increasing efforts to better understand sand lance feeding ecology, distribution and relationship to the rest of the food web. In this regard, funding of our project by the Northeast Sea Grant Consortium proved prescient and a seed for subsequent grants from MIT Sea Grant and the Bureau of Energy Management (BOEM) to continue the work. Surely, the groundswell of interest in sand lance is commensurate with its importance and will enable insights into better management strategies for sensitive ecosystems like those along the U.S. Atlantic coast.
Collaborators on this project are: D. Wiley of the National Oceanic and Atmospheric Administration-Stellwagen Bank National Marine Sanctuary; P. Valentine of the U.S. Geological Survey; and S. Gallagher and J. Llopiz, both of the Woods Hole Oceanographic Institution.
17 January 2018. Since November 2017, we have ongoing experiments with offspring of Northern sand lance (Ammodytes dubius), a winter-spawning forage fish of ecological importance along the North-American Atlantic coast. The clip below shows larvae almost two months after fertilization, developing nicely in 5C water and feeding actively on live rotifers. The experiments, led by Chris Murray for his PhD research, study the CO2 sensitivity of this species in our factorial larval rearing system. To our knowledge, this is the first time that this particular species has been reared that far under experimental conditions. Have a look!
